Please create an account to participate in the Slashdot moderation system


Forgot your password?
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 Internet speed test! ×

Comment Re:I'm missing something about this product, I thi (Score 4, Informative) 78

You must not be in the US. I've never had a card with a chip. Mine doesn't even have raised letters, the only option is the magnetic strip. I suspect the US is the target audience for this.

Chips are coming in the US. The credit card processors are shifting fraud liability in October 2015. Merchants will have to take responsibility for fraud committed on mag stripe transactions, but not chipped ones.

Comment Re:why carry crude to in tanks on moving vehicles? (Score 1) 144

It wouldn't surprise me if some existing refineries have been upgraded to higher capacity though.

This happens.

The recent big example was when Motiva completed the expansion of their Port Arthur refinery. They added 325,000 barrels/day of capacity. If that were built as its own refinery, it would have been the tenth largest in the US. Since it added to an existing refinery, it bumped the refinery up to the largest in the country.

Comment Re:A strange game.... (Score 1) 597

The nearest NK ICBM bunker would be slightly more than 35 miles from Seoul. Please explain how these nukes work that could destroy such a bunker, but not kill most of the 2.4 million people in Seoul.

They work by not having a 35 mile blast radius. The yields of nuclear weapons have fallen significantly from their 1960s peak. A B61 bunker buster couldn't blow up Seoul from the far side of the border under ideal conditions, much less after ground penetration.

Comment Re:How about a picture? (Score 2) 52

is it two binary systems circling a common centre?


Then where do you put a planet in... orbiting in a wide circle around the outside of the stars, figure-8ing between two pairs of stars, some elaborate knot weaving in and out around all 4?

There's a diagram of the inner binary system in the paper. It's near the end.

Two stars orbit each other at a distance of about 0.17 AU. The planet is in a circular orbit around both of them at a distance of 0.64 AU.

The other binary pair is about 1000 AU distant from the first pair. It's irrelevant to the planet's orbit.

Comment Re:More info and video (Score 1) 282

Why does the SLS need to exist? It won't be able to do anything that projected private sector products won't be able to do for a fraction of the cost.

The SLS has one thing the currently-projected private sector boosters don't have: maximum payload capacity. The Falcon Heavy is only supposed to hit 53,000 kg to LEO ("only"). SLS is supposed to be around 100,000 kg. It's basically the Space Shuttle, and those were damn powerful engines. They just had the drawback of hauling 68000 kg of orbiter on every trip.

Falcon X might beat SLS, but that's almost purely concept art at this point. But then, my confidence in the SLS project isn't really any higher.

Comment Re:I don't care. (Score 1) 335

The trail ought to expand and get larger, the farther the source moves away from the thrust. Although there's some uniformity to the seeming circumference of the contrail, it would be larger to the west, and therefore doesn't look like an airliner coming east.

I've seen the inverse argument made. That because things get smaller with distance, it can't be an airliner coming east. The enlarging of the contrail as it disperses is competing with the shrinking with distance. Intuition about which should be winning fails.

And why would there be thrust when the airplane is supposed to be descending (W to E, Honolulu to PHX)?

Because Phoenix is 375 miles from Los Angeles? Flight records for a later run of flight 808 show it beginning its descent about 25 miles west of the California/Arizona border. The flight took a good 50 minutes to get from 37k feet over Los Angeles to arrival on the ground at Phoenix.

They also don't turn the engines off to make the plane go down.

Comment Re:Wow! (Score 2, Informative) 170

Apollo 11 was run from this perspective. Multiple launches (Apollo + Agena) docked in orbit to become the composite lunar spacecraft.

This is incorrect. Each manned Apollo mission used a single Saturn V. (Except for the Apollo 7 test flight, which used a Saturn IB.) Orbital docking occurred between the command/service module and lunar module launched on the same rocket.

Agena boosters were modified to practice docking during the Gemini program, but had no direct involvement in Apollo.

Comment Re:Congress is happy (Score 1) 143

They would have except for Obama de-funding the program. I guess you forgot about that.

You're kidding, right?

Obama has proposed removing funding for the Constellation Program in the 2011 budget. The budget cuts haven't taken effect and are still being argued over. The reason NASA hasn't built them is that NASA is years behind schedule.

Let's see:

SpaceX has delivered a 1960s era liquid fuel rocket designed for LEO. NASA has delivered a 1970s era test vehicle as part of a program to develop a 2010s era launch system.

SpaceX has an almost working satellite launch vehicle. NASA was developing a system for sending people to Luna and Mars.

In five-ish years, SpaceX designed, built, and flew a prototype two-stage rocket. In five-ish years, NASA put a guidance system on an existing STS SRB, and launched a fake second stage.

And you are still confusing two separate launchers. The Ares I is a LEO launch vehicle, an orbital taxi. It can no more get one to the Moon than the Falcon 9. It can ferry people to a lunar transfer vehicle, but so could the Falcon 9.

Yeah, SpaceX has gotten very far using NASA's old technology.

NASA can't get anywhere using NASA's old technology, so SpaceX is still ahead on that score.

Comment Re:Congress is happy (Score 5, Informative) 143

SpaceX started years before the Aries program, used 30 year old technology

I guess you forgot that the Constellation system was supposed to take us back to Luna and then on to Mars and not just the ISS which is the primary target of the Falcon 9 system.

You are misinformed. The Ares I rocket is just a LEO launcher. It is an extended space shuttle solid rocket booster with an upper stage powered by a single Saturn V motor. The technology in it dates to the mid-1970s or even earlier.

The Ares V is a heavy-lift booster that outclasses anything built. Or it would if they'd actually try building one. It is a STS External Tank with five motors off the Delta IV under it and two STS SRBs attached to it. The upper stage is powered by the same Saturn V derivative motor used on the Ares I.

Both programs started development circa 2005 (SpaceX was only founded in 2002). SpaceX has delivered a working launch vehicle. NASA has launched what was literally a slightly modified SRB out of the Space Shuttle inventory as the Ares I-X, and is unlikely to launch the real thing until 2017. The Ares V hasn't even begun to leave the drawing board.

SpaceX has a working satellite launcher that can be made man-rated. The Constellation program has nothing.

Comment Re:Icarus? (Score 2, Informative) 138

Not sure about that. I've seen claims that a lot of the thrust of a solar sail would be due to the solar wind...which would tend to stick, and thus couldn't be tacked against.

Those claims are wrong. The force on a solar sail due to solar radiation pressure is about a thousand times that of the solar wind.

Also, solar cells tend to absorb photons, capturing their momentum, and when they re-radiate it (at a lower frequency) the direction is random.

The solar cells are going to be absorbing a small fraction of the incoming photons. If the sail is designed properly, the rest will be reflected in a controllable direction.

If this is correct, then the simple model of solar sails tacking using reflected light is at least an oversimplification, and possibly so much of an oversimplification that it doesn't properly predict the effects.

Your assumptions are wrong, and the model is correct.

MESSENGER has used its mostly reflective solar panels to make deliberate course changes. The basic physical principle is already proven, not just in the lab, but in space. JAXA is examining the practicality of building large solar sails, not whether they will work at all.

Comment Re:why has he decided to accept it now? (Score 1) 295

2000 was the end of the last decade.

2000 was not the last year of the 1990s, 1999 was.

2000 as the end of the 20th century works because it's counting time since the switch to positive integers, and there was no year zero. Decades such as the 80s, 90s, and whatever we end up calling the period from 2000 to 2009 (inclusive) are not set from the origin, but are based on the tens digit of the year. 2000 may have been part of the 20th century, but it wasn't part of the 90s.

Also note that kimvette made an exception to include a movie released in 2000, which establishes that the conventional 1990-1999 definition of the 90s was intended.

Slashdot Top Deals

"No matter where you go, there you are..." -- Buckaroo Banzai